Fannie Mae, Freddie Mac and the Federal Home Loan Banks all remained heavily dependent on a handful of large lenders for the majority of their mortgage purchase business in 2003, according to a new year-end analysis and ranking by Inside The GSEs. The analysis reveals that all three GSEs derived more than half of their total mortgage business last year from just their top 10 lender customers. And in the case of the FHLBanks,